The present invention is generally related to the field of air ventilation control devices and more specifically to the field of damper arrays for controlling airflow within a duct system.
Damper assemblies are the standard method for regulating airflow within a building's ductwork. Actuated either pneumatically or electrically, an array of damper blades is usually mounted in a frame that itself is either mounted in a duct or is part of the duct itself. Damper assemblies can be classified by both the way in which the blades rotate relative to each other and by the shape of the blades themselves. In the first instance, blades can be arranged to rotate either in opposition to one another (that is, one blade rotates clockwise while adjacent blades rotate counterclockwise) or in parallel (with adjacent blades rotating in the same direction). Choosing between these methods is generally based on the nature of the application and on design preference. Also, damper blades can be formed from a single ply of metal (which is inexpensive) or shaped as an airfoil (which imposes minimum drag but costs more). The choices here generally trade off performance and price.
These choices, however, are difficult to implement because manufacturers uniformly require that these options must be built into the product at the time of fabrication. Clearly, this requirement imposes inordinate inventory requirements on dealers and slows down deliveries. Also, consumers cannot change a unit after it is installed. If a user decides after installing a single-ply damper that it is willing to pay for the improved performance of airfoil blades, it must order a completely new unit.
To date, the prior art has failed to offer a unit that can offer flexibility at low cost. That failure is cured by the present invention.